Proposed solution for [9b2e636361]
Allocate encoding name, so caller of Tcl_RegisterConfig() doesn't need to keep it forever. 
Fix some comments.
formatting, typo
typos. 
On Cygwin, Tcl_SetPanicProc(NULL) should set back the panic proc to its default, which is not NULL.
Correct typo detected by valgrind.
Stop buffer overrun into undefined values detected by valgrind.
Bug [9b2e636361]: Tcl_CreateInterp() needs initialized encodings.
Bug [9b2e636361]: Tcl_CreateInterp() needs initialized encodings.
rebase